High intensity-gas lamp with recirculation means



y 1967 5. M. GiANNINI YETAL- 3,319,097

HIGH INTENSITY-GAS LAMP WITH RECIRCULATION MEANS Original Filed June 6.1962 2 Sheets-Sheet 1 INVENTORS ease/e2 M a/a/v/w/v/ nae/4N0 6. 01/607/z/z/afercz 52/44/140 United States Patent 3,319,097 I-HGH INTENSITY-GASLAMP WITH RECIRCULATION MEANS Gabriel M. Giannini, llndio, Adriano C.Ducati, Santa Ana, and Hubert C. Sullivan, Riverside, Califi, assignorsto Giannini Scientific Corporation, Amityville, N.Y., a cor oration ofDelaware Continuation of application Ser. No. 200,584, June 6, 1962.This appiication Mar. 25, 1965, Ser. No. 445,843 3 Ciaims. (Cl. 313-12)This application is a continuation of application Ser. No. 200,584,filed June 6, 1962, for Lamp Apparatus and Method, now abandoned, whichis a continuation-in-part of application Ser. No. 844,466, filed Oct. 5,1959, for a Forced-Recirculation Lamp Apparatus, now abondoned.

This invention relates to an electric lamp apparatus and methodincorporating means to effect circulation of gas for purposes includingstabilization of an electric are.

An object of the present invention is to provide an improved apparatusand method for generating an extremely high-intensity light by means ofan electric arc.

Another object is to provide an electric lamp device incorporating novelmeans to effect recirculation of gas to an electric arc.

Another object is to provide a novel electric lamp apparatusincorporating forced-recirculation means to recirculate gas whicheffects stabilization and constriction of an electric arc, and in whicheither the are or the heated gas is employed as a source of light.

A further object is to provide a lamp apparatus which is extremelyeffective and efiicient in operation, yet is very simple and compact inconstruction.

A further object is to provide a lamp apparatus incorporating neans toboth clean and cool, in a highly effective manner, thelight-transmissive wall of an arc chamber.

These and other objects and advantages of the invention will be morefully set forth in the following specification and claims, considered inconnection with the attached drawings to which they relate.

In the drawings:

FIGURE 1 is a schematic longitudinal central sectional view of a lampapparatus constructed in accordance with a first embodiment of theinvention;

FIGURE 2 is a transverse section taken on line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged fragmentary longitudinal sectional viewillustrating schematically the electromagnetic pump apparatus;

FIGURE 4 is a transverse schematic sectional view of the pump apparatusof FIGURE 3; and

FIGURE 5 is a schematic longitudinal central sectional view of a lampapparatus constructed in accordance with a second embodiment of theinvention.

Referring first to the embodiment of FIGURES 1-4, the apparatus isillustrated to comprise arcing elements and 11 between which astabilized electric arc may be maintained, one of such elements (number10) having an opening 12 therein so that plasma generate-d by the arcmay be discharged. Transparent wall means 13 are provided to permitlight emanating from the plasma to be transmitted to any desired region.Means 14 are provided to effect forced recirculation of a gas, such asmercury vapor, through the arc space between elements 10 and 11.

More specifically, the arcing element 10 is illustrated as comprising agenerally tubular refractory metal insert adapted to protect the wall ofthe nozzle opening in the metal nozzle electrode 16 of an electricalplasma-jet torch. Arcing element 11, also a refractory metal insert, islocated in the central portion of the generally disc-shaped metal backelectrode 17 of the torch. Electrode 17 is mounted in nozzle electrode16, which is generally cupshaped, in mutually-insulated relationship.The nozzle and back electrodes 16 and 17 are shaped to define betweenarcing elements 10 and 11 an annular gas-pressure chamber 18 coaxialwith the opening 12 in the nozzle insert.

A flanged body 19, formed of metal, is disposed rearwardly adjacent backelectrode 17 and in electrical contact therewith. Both the body 19 andthe back electrode 17 are insulated from the nozzle electrode 16 bymeans of suitable insulation indicated at 20. A retaining ring 21 isthreaded into the nozzle electrode in order to maintain the parts inassembled relationship.

A suitable current source indicated schematically at 23, is connected tothe nozzle electrode and to body 19 in order to effect conduction ofcurrent to the arcing elements 10 and 11. Cooling chambers 24 and 25 areformed, respectively, adjacent arcing elements 10 and 11 in order toeffect cooling thereof. Water may be passed continuously through thecooling chambers 24 and 25 by means of suitable conduits 26 and 27.

The chamber into which the plasma discharges when an arc is maintainedbetween elements 10 and 11, and when gas is passed into chamber 18, hasbeen given the reference numeral 29. Such chamber is partially definedby a wall means 31 shown as being generally tubular in shape and coaxialwith nozzle opening 12. Wall means 31 may be formed of metal and mayincorporate a cooling chamber 32 through which coolant water may becirculated. Chamber 29 is defined not only by the wall means 32 but alsoby the forward wall of nozzle electrode 16 and by thepreviously-indicated transparent wall means 13. The wall means 13 maycomprise a lens which is mounted sealingly over the end of tubular wall32 remote from the torch.

Proceeding next to a description of the forced-recirculation means 14,this is adapted to effect continuous discharge of mercury vapor from thechamber 29, and continuous introduction of mercury vapor at a relativelyhigh pressure and velocity into the gas-pressure chamber 18. Means 14 isshown schematically in FIGURE 1 as comprising a conduit 33 connected tochamber 29 to effect flow of gas therefrom to a suitable condenser 34.Condenser 34- is connected to an electromagnetic pump 35, thearrangement being such that liquid mercury condensed in condenser 34will be pumped by the pump 35 into a suitable vaporizer 36 where theliquid mercury is converted into mercury vapor.

The resulting mercury vapor is passed from vaporizer 36 through conduitmeans 37 to a passage 38 formed in the nozzle electrode 1-6 tangentiallyof pressure chamber 18. Mercury vapor entering chamber 13 tangentiallyflows vertically therein and, after being heated by the arc, dischargesthrough the nozzle opening 12 into chamber 29. Such discharge intochamber 29 is primarily, as previously indicated, in the form of aplasma jet which is composed of neutral gas, ions and electrons, at hightemperatures.

Referring next to FIGURES 3 and 4, the electromagnetic pump 35 isschematically illustratedas comprising a tube 39 having electrodes 41mounted therein at diametrically opposite portions thereof. Tube 39 isformed of a suitable insulating material, so that electricity passingbetween the electrodes 41 is conducted not through the tube but throughthe liquid mercury therein. Magnet means, such as the illustratedelectrom agnets 42 and 43, are mounted on diametrically opposite sidesof tube 39 in the same plane (perpendicular to tube 39) as electrodes 41but rotated relative to a line between the electrodes.

The lines of magnetic force passing between the electromagnets 42 and 43are disposed at right angles tothe direction of current flow through themercury between electrodes 41. It follows that when a suitable directcurrent source 44 is connected to electrodes M, and when the polaritiesof the electrodes and the poles of the magnets are properly related, aforce will be present in tube 39 tending to force the mercury towardvaporizer 36 or to the left as viewed in FIGURES l and 3.

Suitable unshown auxiliary equipment, such as a check valve between pump35 and vaporizer 36, may be provided in or adjacent the tube 39.

To summarize briefly the operation of the embodiment of FIGURES 1-4, theelectromagnets 42 and 43 are suitably energized from an unshown directcurrent source, and current source 44 (FIGURE 3) is applied to effectcurrent flow through the liquid mercury in tube 39. Since such currentflow is in a direction transverse to the lines of magnetic force betweenthe magnets 42 and 43, mercury is forced into the vaporizer 36 where itis vaporized. The resulting mercury vapor is conducted through conduit37 and passage 38 (FIGURE 2) tangentially into pressure chamber 18,where it flows vortically and then passes out the nozzle opening 12 intochamber 29.

Current source 23 is then applied, and an arct is suitably initiatedbetween the arcing elements lid and ill. The are passes through thecanal in the vortically-flowing mercury vapor and is stabilized thereby.The mercury vapor and the electric arc combine to effect generation ofthe plasma jet which discharges at high velocity and temperature intothe chamber 29. The plasma jet constitutes a source of light, such lightbeing transmitted through the lens 13 to any desired region.

The mercury vapor thus introduced into chamber 29 is cooled by means ofwater flowing through the wall means 31. Such cooling action, and theaction of the condenser 34, convert the mercury vapor back into liquidmercury which is then introduced into the electromagnetic pump 35 forrecirculation as described.

Embodiment of FIGURE Referring next to FIGURE 5, the arcing elements areseen to comprise coaxial metal electrodes 45 and 46. The electrodes arecylindrical in shape, and at least one, shown as number 45, is providedwith an axial passage or opening 47 through which plasma may bedischarged into a chamber or conduit 48. The chamber 48 may, if desired,be made to correspond to the chamber 29 shown in FIG- URE 1 in orderthat light emanating from the plasma discharged through passage 57 maybe transmitted to a desired area.

A tubular insulating element 49 is mounted coaxially around both of theelectrodes '45 and 45, the relationship being such that a cylindricalchamber 51 is formed coaxially of the passage 47. Chamber 51 is definednot only by the interior wall of insulator 49 but also by a suitablelens or other transparent window element 52. Element 52 has an innerwall which is coincident with the cylinder containing the inner wall ofinsulator 49, so that the vortical flow of gas in chamber 51 is notaffected adversely.

A suitable current source 53 is connected to the electrodes 45 and 46through current conductors and also through suitable fiange portions 54formed integral with the electrodes. Sealing means 55 are provided toprevent escape of gas from chamber 51 except through passage or opening47.

The recirculation means illustrated in FIGURE 5 may be identical to thatshown and described with relation to FIGURES 14. Thus, chamber 48 isconnected to condenser 34 so that the mercury vapor will be condensedtherein. The electromagnetic pump 35 is then employed to pump liquidmercury into the vaporizer 36, such liquid mercury then being vaporizedand conducted toa passage 56 formed through insulator 49 tangentially ofchamber 51. The cross-sectional area of passage 56 should be smallerthan that of the passage 47 through which plasma is discharged intochamber 48.

To summarize the operation of the embodiment of FIGURE 5, theelectromagnetic pump 35 is set in operation to efiect flow of mercuryvapor through tangential passage 56 into annular chamber 51. Such vaporflows vortically and results in the presence of a canal axially ofchamber 51 between the electrodes 45 and 46. The current source 53 isthen applied, and a suitable means (such as a momentary pulse of highvoltage) is employed to initiate an electrical discharge or are betweenthe electrodes 45 and 46 through the canal defined by the whirling gas.Such arc or discharge is maintained continuously and is stabilized bythe vortically-flowing mercury vapor. The gas and the arc combine tocreate plasma which flows through the opening 47 into chamber 48. Themercury vapor is then condensed in condenser 34, and the resultingliquid mercury is, pumped by pump 35-into the vaporizer 36.

Suitable cooling means, not shown may be provided both for theelectrodes 45 and 46, and for the wall of chamber 48.

The described forced recirculation means may also comprise any suitablepump device for pumping a suitable gas through the above-describedrecirculation circuit. Such pump device may pump various suitable gases(such as krypton, xenon or argon) in place of mercury vapor. Thedescribed current source is preferably a DC. source adapted to deliver alarge current.

Various embodiments of the present invention in addition to what hasbeen illustrated and described in detail, may be employed withoutdeparting from the scope of the accompanying claims.

We claim:

1. An electric plasma lamp, which comprises:

means to define a first gas chamber having an outlet opening therefrom,

first and second electrode means having arcing portions disposed in saidfirst chamber, means to define a second gas chamber communicating withsaid opening on the opposite side thereof from said first chamber,

means to maintain a continuous electric are between said arcing portionsin said first chamber,

means independent of said arc to effect forced recirculation of mercuryvapor into said first chamber and thence through said opening into saidsecond chamber and thence back into said first chamber,

said recirculation means including means to effect condensation of saidmercury vapor to form liquid mercury, means to efiect flow of electriccurrent through said liquid mercury in a predetermined direction, meansto create a magnetic field extending through said liquid mercury in adirection at right angles to said predetermined direction, therebycreating a force effecting pumping of said liquid mercury, and means tovaporize said pumped liquid mercury and introduce the resulting mercuryvapor into said first chamber, said recirculation means and said meansto define said first chamber being so related to each other and to saidelectrodes that the gas flow in said first chamber is vortical aboutsaid are, and light-transmissive wall means to permit light generated asthe result of said are to be transmitted away from the lamp.

2. A high-intensity light, which comprises:

wall means to define a gas-pressure chamber, at least a portion of saidWall means being formed of transparent material,

first and second electrode means having arcing portions disposed tomaintain an electric arc in said chamber,

inlet means to introduce into said chamber a gas which is the vapor of aliquid,

outlet means to drain said gas continuously from said chamber,

means to maintain an electric arc in said chamber between said arcingportions to thereby generate light for transmission through saidtransparent material,

said arc heating said vapor,

condenser means to receive hot vapor from said outlet means and condensesaid hot vapor into a liquid,

evaporator means to vaporize said liquid into a vapor,

means to pump said liquid from said condenser means to said evaporatormeans, and

means to pass said vapor from said evaporator means to said inlet means.

3. Apparatus for generating high-intensity light, which comprises:

wall means to define an arc chamber,

at least a substantial portion of said wall means being formed oftransparent material whereby to transmit light outwardly from saidchamber, at least a major portion of the interior surface of said wallmeans being a surface of revolution about a central axis, first andsecond elongated electrodes having arcing end portions disposed in saidare chamber at spaced points along said axis whereby to maintan anelectric arc therealong, means to maintain continuously an electric arebetween said arcing portions, gas-inlet means to introduce gascontinuously into said arc chamber, gas-outlet means to drain gascontinuously from said chamber,

said gas-inlet and gas-outlet means each including passage meansadjacent said chamber and directly communicating therewith,

said passage means of said gas-inlet and gasoutlet means being orientedto effect vortical flow of said gas in said chamber about said axiswhereby to stabilize said arc along said axis in the canal through theverticallyflowing gas, said passage means of said gas-outlet meansextending through one of said electrodes and being disposed adjacentsaid are, said passage means of said gas-inlet means being disposed toeifect flow of relatively cool incoming gas along said interior surfaceof revolution whereby gas must flow radially-inwardly before drainingthrough said passage means of said gas-outlet means, and means to coolsaid gas and to effect recirculation thereof from said gas-outlet meansto said gas-inlet means.

References Cited by the Examiner UNITED STATES PATENTS 3/1960 Gianniniet al. 313-321 3,064,153 11/1962 Gage 31322 3,233,147 2/ 1966 Ducati315111 JAMES W. LAWRENCE, Primary Examiner.

C. R. CAMPBELL, Assistant Examiner.

1. AN ELECTRIC PLASMA LAMP, WHICH COMPRISES: MEANS TO DEFINE A FIRST GASCHAMBER HAVING AN OUTLET OPENING THEREFROM, FIRST AND SECOND ELECTRODEMEANS HAVING ARCING PORTIONS DISPOSED IN SAID FIRST CHAMBER, MEANS TODEFINE A SECOND GAS CHAMBER COMMUNICATING WITH SAID OPENING ON THEOPPOSITE SIDE THEREOF FROM SAID FIRST CHAMBER, MEANS TO MAINTAIN ACONTINUOUS ELECTRIC ARE BETWEEN SAID ARCING PORTIONS IN SAID FIRSTCHAMBER, MEANS INDEPENDENT OF SAID ARC TO EFFECT FORCED RECIRCULATION OFMERCURY VAPOR INTO SAID FIRST CHAMBER AND THENCE THROUGH SAID OPENINGINTO SAID SECOND CHAMBER AND THENCE BACK INTO SAID FIRST CHAMBER, SAIDRECIRCULATION MEANS INCLUDING MEANS TO EFFECT CONDENSATION OF SAIDMERCURY VAPOR TO FORM LIQUID MERCURY, MEANS TO EFFECT FLOW OF ELECTRICCURRENT THROUGH SAID LIQUID MERCURY IN A PREDETERMINED DIRECTION, MEANSTO CREATE A MAGNETIC FIELD EXTENDING THROUGH SAID LIQUID MERCURY IN ADIRECTION AT RIGHT ANGLES TO SAID PREDETERMINED DIRECTION, THEREBYCREATING A FORCE EFFECTING PUMPING OF SAID LIQUID MERCURY, AND MEANS TOVAPORIZE SAID PUMPED LIQUID MERCURY AND INTRODUCE THE RESULTING MERCURYVAPOR INTO SAID FIRST CHAMBER, SAID RECIRCULATION MEANS AND SAID MEANSTO DEFINE SAID FIRST CHAMBER BEING SO RELATED TO EACH OTHER AND TO SAIDELECTRODES THAT THE GAS FLOW IN SAID FIRST CHAMBER IS VORTICAL ABOUTSAID ARC, AND LIGHT-TRANSMISSIVE WALL MEANS TO PERMIT LIGHT GENERATED ASTHE RESULT OF SAID ARC TO BE TRANSMITTED AWAY FROM THE LAMP.